SQL Syntax
Menu
SQL Syntax
SQL has a syntax that is used to interact with databases. Here are some of the basic syntax rules and components of SQL:
- SQL commands are written in uppercase or lowercase letters. SQL is not case-sensitive, but it is a common practice to write SQL commands in uppercase letters to make them easily distinguishable from the data.
- SQL commands are terminated by a semicolon (;) at the end of each statement.
- SQL commands can be split into multiple lines for readability, but this is not necessary.
- SQL keywords are reserved words that are used in SQL commands and cannot be used for table or column names. Some examples of SQL keywords are SELECT, FROM, WHERE, INSERT, UPDATE, DELETE, and JOIN.
- SQL identifiers are used to name tables, columns, and other database objects. Identifiers must follow certain rules, such as being enclosed in single quotes or square brackets, depending on the DBMS being used.
- SQL comments are used to add notes to the code that are not executed by the database. Comments are denoted by two hyphens (–), and anything after them on the same line is ignored.
Here is an example of a basic SQL command using the SELECT statement to retrieve data from a table:
SELECT column1, column2, column3
FROM table_name
WHERE condition;
In this example, SELECT is the keyword used to retrieve data from the specified columns in the table_name. The WHERE clause is used to filter the results based on a specified condition.
SQL syntax can become more complex depending on the task being performed, such as creating tables, inserting data, and joining tables together. However, the basic syntax rules and components remain the same.
Menu
Join To Get Our Newsletter